AWD VS 4WD

[racsan]

The awd escape (gen 2 at least) has some sort of slip clutch for the rear axle, I was changing tires and had a tire completely off the ground as I was tightening it, could turn the tire! noticeable resistance but could turn it. Ive never had a traction issue with the escape, I run winter tires during the cold months, it absolutely eats through the snow. Ive never been able to do a 4-wheel powerslide through a turn like I could in my old ‘93 4.0 4x4. But then I also dont drive as hard as I used to either.

 

[JohnnyO]

My 08 Sport Trac had three buttons. 4-Auto, 4-Hi, and 4-Low. 4-Hi and 4-Low were the usual locked in 4wd. 4-Auto was normally 2wd but the computer would kick in the front axle if it detected wheel spin. It was jerky and unpredictable and I hated it so if there was snow I’d just lock it in 4-Hi and usually turn the traction control off too. It was NOT AWD despite what some owners believe thanks to a mistake in some early Ford literature and the fact that Adrenalins don’t have any buttons and run in 4-Auto all the time.

 

[rusty ol ranger]

My 08 Sport Trac had three buttons. 4-Auto, 4-Hi, and 4-Low. 4-Hi and 4-Low were the usual locked in 4wd. 4-Auto was normally 2wd but the computer would kick in the front axle if it detected wheel spin. It was jerky and unpredictable and I hated it so if there was snow I’d just lock it in 4-Hi and usually turn the traction control off too. It was NOT AWD despite what some owners believe thanks to a mistake in some early Ford literature and the fact that Adrenalins don’t have any buttons and run in 4-Auto all the time.

My 97 and 98 Expeditions had that auto setting, but also a 2 hi. So it said "2hi A4WD 4hi 4lo"

I used the A4WD quite often...was nice when the roads were iffy and i could take off eaiser from lights and shit, without running it in actual 4

But when shit got deep it got locked in. Thats when id notice the jerkyness

 

[sgtsandman]

Most (like @sgtsandman 's qualification, most, not all) AWD is FWD with clutches/viscous fluid to add in rear axle, because that is the cheap less expensive way to do it. As the rear axle is driven off the passenger's half shaft, the transmission differential "sees" 75% load on passenger's 1/2 shaft. As transmission has open differential, when you get in really bad conditions with only 25% of load on driver's side, the driver's front tire spins out. Hondas, VWs, FWD based Fords (Escapes, new Explorers), Jeep Patriot, etc all use this system.

AWD is useful because rarely does one wheel have zero (0) traction, so while is it send 97% to one wheel, it is send 1% each to the other 3 and hopefully that keeps you moving. My Ranger, with the NP242, will sit there in mud spinning both rear wheels (I have locker in rear axle) with transfer case differential open (AWD setting on transfer case). Pull it from AWD to 4WD to cage the differential and off we go. (Was rather embarrassing <2cm mud and I was going nowhere until I put it in 4WD).

The electronics, both sensing and control, are so good at this point, that mfrs want open differentials in both transfer case and axles as any mechanical override is messing the electronics.

The only exception I know of in the unibody AWD vehicles is Subaru. Most of them are still RWD based, if not all. I haven't followed anything on them in years, so it is possible that has changed. I mean, they did use to have a true 4X4 drivetrain back in the day but those days are long gone.

I do agree that the FWD based units are certainly more cheaply built than a 4X4. Frankly, I prefer working on a real 4X4 better. Less headaches over all and the parts when things do break tend to be cheaper. Try buying a replacement propeller shaft for an early CR-V when the support bearing is failing and the support bearing is not a replaceable part.

 

[Josh B]

AWD does not send power to other wheels when power is lost in primary drive tires - because it has differential in transfer case, it send the power to the tire with the least traction. Which is why my daughter's Escape with AWD can be stuck with one wheel on ice, yet the other 3 are on dry pavement.

Now, with 21st century electronics, mfrs may install an AWD transfer case, then monitor wheel speed. If wheel appears to lose traction, they take advantage of ABS system apply brake to that wheel and that causes power to go to the other wheels. Just like applying parking brake judiciously did on rear wheel vehicles with open different back in the day. The different terrain modes, control how much wheel spin is allowed before the traction control comes into effect. If traction control is done really well - e.g. BMWs, you don't even notice it is occurring.

If the transfer case in your jeep has 49/51 split in high range, if the differential is still open in low range, it still has 49/51 split there. Only if differential is locked in low range will it send power 50/50.

Thanks Don, I've only got to read one, my internet went down just after sending my last post and it will take me some time to get caught up, maybe a day or so. Thanks to everybody who has responded, I really do appreciate the volumes of information you have provided, it will take me some time to catch up a bit.

Pls keep those cards and letters coming tho, it will no doubt benefit a lot more than just me, who have just arrived at 4WD, much less encountered the many other adaptations of it

 

[Josh B]

Thanks so much fellas for your insights into this. I suppose at this time I see no reason to believe I'll be using any of it myself, except maybe the rear DIFF. If it's what I think I've found is almost identical excepting being a couple inches wider, which I suppose is cool, and the drums are rotors instead, I think that too is a step up eh?

Thanks again so much

 

[19Walt93]

4x4 requires more thought to operate. with AWD you stick it in gear and step on the pedal. If you've driven in 4x4 on snow covered roads and gotten into a 4 wheel skid, you'll almost never drive distances in 4x4 again- once the skid starts you're a passenger with no control. We had customers run in 4x4 over dry pavement a few times with bad results. LaSallette seminary in Enfield, NH had a maintenance guy who did their plowing and he decided to drive it to our shop one day after plowing without taking it out of 4x4 and blew the front differential into pieces. Most often when people drove on pavement in 4x4 they would twist up a driveshaft instead. A restaurant owner in Hanover bought a new mid 90's Bronco with a Fisher plow. He was a city boy and had never plowed before so he spent an afternoon "practice plowing" his parking lot. In August on bare, hot pavement. That was one of very few New Process transfer cases I ever saw fail. You can't fix stupid but we were able to fix the damage caused by stupid.

 

[sgtsandman]

Thanks so much fellas for your insights into this. I suppose at this time I see no reason to believe I'll be using any of it myself, except maybe the rear DIFF. If it's what I think I've found is almost identical excepting being a couple inches wider, which I suppose is cool, and the drums are rotors instead, I think that too is a step up eh?

Thanks again so much

The axles with the disc brakes are wider because the over all brake setup is thinner than the drum brake setup. From what I remember, it’s only a matter of an inch or two, but they are wider.

 

[rusty ol ranger]

4x4 requires more thought to operate. with AWD you stick it in gear and step on the pedal. If you've driven in 4x4 on snow covered roads and gotten into a 4 wheel skid, you'll almost never drive distances in 4x4 again- once the skid starts you're a passenger with no control. We had customers run in 4x4 over dry pavement a few times with bad results. LaSallette seminary in Enfield, NH had a maintenance guy who did their plowing and he decided to drive it to our shop one day after plowing without taking it out of 4x4 and blew the front differential into pieces. Most often when people drove on pavement in 4x4 they would twist up a driveshaft instead. A restaurant owner in Hanover bought a new mid 90's Bronco with a Fisher plow. He was a city boy and had never plowed before so he spent an afternoon "practice plowing" his parking lot. In August on bare, hot pavement. That was one of very few New Process transfer cases I ever saw fail. You can't fix stupid but we were able to fix the damage caused by stupid.

With a part time system in snow id usually run 2 untill i was stuck, yank it into 4 and pull myself out, then hit 2 again.

Id rather get stuck in 2 then get stuck in 4.

If it was a mudhole or something off road id usually switch to 4 before the hole lol

 

[JoshT]

Thanks so much fellas for your insights into this. I suppose at this time I see no reason to believe I'll be using any of it myself, except maybe the rear DIFF. If it's what I think I've found is almost identical excepting being a couple inches wider, which I suppose is cool, and the drums are rotors instead, I think that too is a step up eh?

Thanks again so much

Rear diff/axle from what? What are you working on/doing? I've been wondering that every time I've looked at this thread. Your profile talks about a '93 Ranger 4.0L.

You start off talking about 4wd in the Ranger vs AWD in the Explorer. I don;t see you talking about a 5.0L explorer or a drivetrain swap anywhere and those were the only ones with an AWD transfercase, which weouldn;t bolt up behind your current transmission. V6 Explorers weren't AWD.

Anyway, onto the question quoted above...

You're talking about using a disc brake rear axle. The only RBV disc axles were the second gen Explorer and '10-'11 Rangers. Ok, later Explorers too, but those were IRS.

If you;re talking about the Explorer axle, along with other changes the width was increased for stability. This was part of the solution for the percieved roll over issues found in the Bronco II that proceeded it.

If you;re talking about a the 10-11 Ranger axle, the overall axle width should be the same as the earlier axles.

For both the Explorer and the Ranger, relative to its platform the WMS to WMS width of the axle is the same between the disc and drum versions. That is a slight oversimplification considering the generational width changes in the Ranger, but close enough. What is changed from drum axles to their respective disc brake successor is the axle housing width, which as sgtsandmansaid will be wider on the disc axle to account for the narrower brake assembly.

So no, the width difference isn't due to the brakes, but due to the platform. Be aware that to use an Explorer axle on the Ranger will require other changes to the axle. Spring perch relocation, shock mounting tabs, etc...

 

[Josh B]

Thanks Josh,
That's a 96 Explorer w/ 4.0, which I origionaly purchased for the engine itself but then got to thinking maybe it was restorable until the front seal on the transmission blew. I don't know what all is still usable but expect both differentials and the TC, possibly even the body if anyone needed one with airbags still in it. Also good glass all around and a full length cargo rack. One thing especially gets me is 4 large doors and X large rear hatch, and ten large windows and large luggage rack and not a single leak
It got horrible mileage tho, maybe 12/14 tops.

 

[JoshT]

I don't know what is normal MPG for an Explorer, but I'd never expect it to be stellar. Honestly I normally get around 15 in my 99 4.0L 4x4 Ranger, but I imagine that is mostly due to my driving style.

I definitely understand the appreciation of the additional space, that's why I like the extended cab Rangers to the Regular cab in the round body styles. I don't have a need for a back seat, but the extra room is nice. I still prefer the regular cab square bodies though.

Your 93 Ranger has a different type of front axle and the differential isn't interchangeable. but the rear can be used with some modifications. At this point I'm a little confused at to what transfer case the Explorer has. If it's a straight 4wd BW1354 transfercase then it might be usable, but if it is the A4WD BW4405 then I doubt it would be worth the effort.

It sounds restorable, it's just a question of it's it's worth the expense and effort to you. I know that it would not be for me. If you have the time and space to store and part out I respect and commend you for doing so. Too many good, usable parts end up crushed because they were delivered to the local wrecking yard.

 

[rusty ol ranger]

A tranny is like 500 bucks from a junkyard

 

[Josh B]

I don't know what is normal MPG for an Explorer, but I'd never expect it to be stellar. Honestly I normally get around 15 in my 99 4.0L 4x4 Ranger, but I imagine that is mostly due to my driving style.

I definitely understand the appreciation of the additional space, that's why I like the extended cab Rangers to the Regular cab in the round body styles. I don't have a need for a back seat, but the extra room is nice. I still prefer the regular cab square bodies though.

Your 93 Ranger has a different type of front axle and the differential isn't interchangeable. but the rear can be used with some modifications. At this point I'm a little confused at to what transfer case the Explorer has. If it's a straight 4wd BW1354 transfercase then it might be usable, but if it is the A4WD BW4405 then I doubt it would be worth the effort.

It sounds restorable, it's just a question of it's it's worth the expense and effort to you. I know that it would not be for me. If you have the time and space to store and part out I respect and commend you for doing so. Too many good, usable parts end up crushed because they were delivered to the local wrecking yard.

It would have to be someone interested in that model or type vehicle due to having a substantial amount of parts already, the main interest I thought might be there were the airbags.
Other than someone wanting to use it on restoring would just be the axles, the TC, various driveline parts, wiring harness. I won't initially be using the intake off of it on my Ranger. I might work some deal with my cousin or something

 

[Josh B]

A tranny is like 500 bucks from a junkyard

Just before the pandemic and the last election they were 150.00 @ Picker's, I got one for $75.00 because they had a deal I saw on their web page giving 50% off your first purchase by signing up for their news letter